In this context, in fact, increasingly common is the use of glues instead of the more conventional welding technique, above all as regards assembly of motor-vehicle bodies. Connection via glues enables, in fact, connection together also of non-metal parts and, consequently, enables introduction, in the composition of the body, of new materials, such as carbon fibres, fibreglass, and polymeric materials in general.
The above methodology presents a series of critical aspects that have been already identified and tackled by known gluing systems. For instance, in the use of thermally activated glues, once the two components have been coupled with the layer of glue set in between, it is of fundamental importance to ensure that the glue reaches a predetermined temperature and maintains it for a sufficient time for the cross-linking process, designed to establish the connection between the two components, to be completed. In this connection, the German document No. DE19941996A1 describes, for example, a gluing system that envisages heating units having the function of operating on the two components already glued together so as to initiate and bring the aforesaid cross-linking process to a given stage such that it will then be possible to handle the two components assembled together, throughout the subsequent stations of the assembly line, without any risk of detachment of the two components.
Once again as regards the problem of cross-linking of the glue, the German document No. DE19941996A1 describes a head for application of glue carried by a robot arm, which is equipped with heating means, which operate for heating the glue, immediately after it has been applied on the component.